This patent for the Utility Model refers to a new disposition that was introduced to a hydropneumatic device which is used to lift and support haulers and semi-haulers, whereby such device has been projected to offer more easiness to the driver during operations through the increase of speed, as well as durability in the set.
The state of the technique, which is the reason for this perfected construction, is known by means of patents MU 8201270-9 and MU 8203002-2, from the same petitioner.
Patent MU 8201270-9 refers to a hydraulic lifting device for haulers and semi-haulers that is composed of a squared structure in steel, fixed by means of screws at the front of a semi-hauler, which supports the implement and also helps in its elevation, facilitating the coupling or uncoupling of a towing vehicle; it consists of a independent reservoir for hydraulic oil on each device, on both the left and right sides of the hauler or semi-hauler, operated by means of a lever that activates an eccentric shaft when it is turned, thus resulting into descendent vertical movement in the mechanical hydraulic injector which is operated manually, which in turn dislocates a volume of oil that has been determined for the bottom of the hydraulic cylinder, dislocating then the inner casing of the levering equipment. The return of the hydraulic injector and the shaft for the cylinder is performed by means of compression springs and worm gear traction. Therefore, it is a manually operated system that depends upon human propulsion.
In a different fashion, Patent MU 8203002-2 consists of a form of an automated hydraulic lifting device for haulers and semi-haulers, that is to say, it is provided with a continuous pneumatic pump and the operation is made by means of an air compressor coming from the towing vehicle. The hydropneumatic operation produces the telescopic movement in the hydraulic cylinder and the consequential descending movement of the telescopic boom. The return to the hydraulic cylinder and lifting of the telescopic boom occurs by the entry of air in the cylinder and the reestablishment of the inner air pressure. Therefore, it is an automated system that uses a continuous pneumatic pump and air compression, and no longer human propulsion and worm gear traction which present low durability due to wear as a result of the movement.